This invention relates generally to computer systems, and more particularly to graphical user interfaces for computer systems.
Graphical user interfaces or GUI are becoming increasingly popular with computer users. It is generally accepted that computers having graphical user interfaces are easier to use, and that it is quicker to learn an application program in a GUI environment than in a non-GUI environment.
A relatively new type of computer which is well suited for graphical user environments is the pen-based or pen-aware ("pen") computer system. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-aware computer system is one which has been modified to accept pen inputs in addition to traditional input methods. A pen computer system is often housed in a relatively flat enclosure, and has a dual-function display assembly which serves as both an input device and an output device. When operating as an input device, the display assembly senses the position of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU. When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function display assemblies of pen-based computer systems permit users to operate the computer as a computerized notepad. For example, graphical images can be input into the pen-based computer by merely moving the stylus across the surface of the screen. A stroke is defined as the engagement of the screen with a stylus, the movement of the stylus across the screen (if any), and its subsequent disengagement from the screen. As the CPU senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen, i.e. that the stylus is "inking" an image on the screen. With suitable recognition software, text and numeric information can also be entered into the pen-based computer system in a similar fashion. Besides serving as a notepad, pen computers can provide a number of useful functions, such as serving as an address book, an appointment calendar, a to-do list, etc.
Text, graphical pictures or other images ("images") are often displayed on a computer screen by an application program. It is sometimes desirable to add annotations or "notes" to these images. Notes include comments, explanations, observations, doodles, etc. typically written near a section of displayed images. The notes might remind the reader of a related topic, comment on a section of text, or otherwise indicate to the reader the importance or relevance of a specific area in the document or data file being viewed.
Notes, by their nature, should be simple and easy to add to a document. Since notes are generally extra commentary or explanation of a section of a document or data file, they are not typically entered into the document itself, nor are they printed when the document is printed.
Pen computer systems are especially well suited for use of notes in text and other documents. Portable pen computer systems in particular are ideal to view a document at the user's convenience and add notes where needed. The pen input mechanism, typically a stylus, is also well suited to enter notes, since the user can simply and quickly write comments and words as "ink" in a section of a document as desired without having to use a relatively cumbersome input device, such as a keyboard.
Application programs can be modified for pen-based and pen-aware computer systems which could provide a note-taking capability. However, this is an expensive project for application developers, and requires end users to buy updated versions of their application programs.
What is needed is an annotation or note utility program that allows the user to attach notes to an unmodified application program. The note utility should be able to be used with both pen-compatible and non-pen-compatible software.